Abstract: In several fields, modern academics trumpet the contingency of social science and the indeterminacy of institutional structures. The Japanese experience during the first half of the 20th century, however, instead tracks what much-derided chauvinists have claimed all along: modern legal institutions largely trump indigenous organizational frameworks, and modern rational-choice theory nicely predicts how people respond to such institutions. As orientalist as it may seem, such theory goes a long way toward explaining the real world in which we live.